For medical imaging examinations, such as magnetic resonance examinations, exact positioning of the patient within a patient examination area of the medical imaging apparatus is necessary. For this purpose the medical imaging apparatus has in particular a patient support apparatus of the medical imaging apparatus, a position detection apparatus for detection of a position of a table with respect to a base unit of the patient support apparatus. The patient is supported on the table for the medical imaging examination and is moved together with the table into the patient scanning area.
Previous position detection apparatuses include an optical sensor unit and a punched tape mask, which is designed so as to be movable with respect to the optical sensor unit. The optical sensor unit includes at least one first fiber optic element for supplying light signals to the punched tape mask and at least one second fiber optic element for returning light signals which penetrate the punched tape mask. The at least one first fiber optic element is designed separately from the at least one second fiber optic element here. Furthermore, it is customary for a position detection measurement to be made at two different positions, so an absolute position of the table can be determined from the detected signals. As a result of this the position detection apparatus takes up a great deal of space, however, within the patient support apparatus.